Beniya Atsushi, Higashi Shougo, Ohba Nobuko, Jinnouchi Ryosuke, Hirata Hirohito, Watanabe Yoshihide
Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi, 480-1192, Japan.
Toyota Motor Corporation, 1200 Mishuku, Susono, Shizuoka, 410-1193, Japan.
Nat Commun. 2020 Apr 20;11(1):1888. doi: 10.1038/s41467-020-15850-4.
Platinum nanocatalysts play critical roles in CO oxidation, an important catalytic conversion process. As the catalyst size decreases, the influence of the support material on catalysis increases which can alter the chemical states of Pt atoms in contact with the support. Herein, we demonstrate that under-coordinated Pt atoms at the edges of the first cluster layer are rendered cationic by direct contact with the AlO support, which affects the overall CO oxidation activity. The ratio of neutral to cationic Pt atoms in the Pt nanocluster is strongly correlated with the CO oxidation activity, but no correlation exists with the total surface area of surface-exposed Pt atoms. The low oxygen affinity of cationic Pt atoms explains this counterintuitive result. Using this relationship and our modified bond-additivity method, which only requires the catalyst-support bond energy as input, we successfully predict the CO oxidation activities of various sized Pt clusters on TiO.
铂纳米催化剂在CO氧化这一重要的催化转化过程中起着关键作用。随着催化剂尺寸减小，载体材料对催化作用的影响增大，这会改变与载体接触的Pt原子的化学状态。在此，我们证明，第一层团簇边缘处配位不足的Pt原子通过与AlO载体直接接触而带正电，这影响了整体的CO氧化活性。Pt纳米团簇中中性Pt原子与阳离子Pt原子的比例与CO氧化活性密切相关，但与表面暴露的Pt原子的总表面积无关。阳离子Pt原子的低氧亲和力解释了这一违反直觉的结果。利用这种关系以及我们改进的键加和方法（该方法仅需催化剂 - 载体键能作为输入），我们成功预测了TiO上各种尺寸的Pt团簇的CO氧化活性。
